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-   -   Continuous duty, non-thermally compensated alternator: options? (http://www.sailnet.com/forums/electrical-systems/104748-continuous-duty-non-thermally-compensated-alternator-options.html)

Rusty123 10-15-2013 10:41 AM

Continuous duty, non-thermally compensated alternator: options?
 
I damaged my stock Yanmar/Hitachi 55 amp alternator. I'm pretty sure it can be repaired, but this seems like a good time to upgrade.

I don't really need fill blown external regulation, but I would like to be able to deliver rated output if/when the battery bank will accept it. (My understanding is that my Hitachi will only deliver rated output for a short time, and then will throttle back due to temperature compensation). I also would like to stay somewhere around 55 amps, since my engine is only 15 hp (2qm15).

I've looked at the Balmars, Electromaxx, etc., but the really seem like overkill for my application (and very expensive). Any suggestion regarding a more mundane, but capable unit?

FarCry 10-15-2013 04:06 PM

Re: Continuous duty, non-thermally compensated alternator: options?
 
How big is your battery bank? What loads do you have on the boat? Refrigeration? Incandescent lighting? Fans? How long do you want to be away from shore power?

I was in your position a few years ago on my Bombay Clipper 31. I spent a few weeks a year on it with the original 35 amp alternator. No fridge. I swapped all the lights out for LEDs which greatly extended time between charging.

Eventually I added a fridge, installed 2 golf cart batteries, a Victron battery monitor and a Kyocera 145 watt solar panel. Unless I had 3 straight days of rain, I never had to run the engine again for charging. Boat was electrically self sufficient. Ice cold drinks year round from the sun was a great investment.

Not know your sailing area, I think switching to LEDs, efficient fans, etc., is a better use of funds than spending much on a higher end alternator. I ran an 80 amp Hitachi on my little 2QM for awhile and it was too much load if the batteries were down. In other words, I'd suggest reducing your loads (if possible) before increasing the charging capacity.

Rusty123 10-15-2013 07:47 PM

Re: Continuous duty, non-thermally compensated alternator: options?
 
Good questions, and suggestions.

I'm primarily a day sailor, only spending a maximum of three or four days off shore power a couple times each year. Bank is 230 AH, which has been adequate for my loads ( refer, led lights, radio, plotter, pretty standard). Honestly, I'm pretty happy with my electrical system - the only reason I'm considering an upgrade is that I am forced to either repair my current alternator, or buy a new one. Since the Hitachi design seems marginal for deep cycle use, I'm looking for alternatives. But I certainly don't want to spend big bucks at this point.

Russ

Rusty123 10-17-2013 10:59 PM

Continuous duty, non-thermally compensated alternator: options?
 
I recently installed a battery monitor, so I developed a detailed energy budget today. Here's what I came up with:

Device Daily Use
Refrigerator. 28.8
Stereo. 15.0
Anchor Light. 7.6
Chartplotter. 5.4
LPG Solenoid. 4.0
Tillerpilot 3.8
Tablet Charger. 4.5
Fan 3.5
Lamp (LED) 3.5
VHF Radio 3.4
Propane Sniffer. 1.5
Navigation Lites. 1.1
Depth Sounder. 0.8
Cell Charger 0.4
Total 83.4

My house bank of two golf cart batteries is 220 AH, which is 2.6 times my daily load. Perhaps a bit undersized, but not by much (might be able to make up the difference with some additional refer insulation).

Assuming an alternator charge rate of 25%, I should have an alternator of about 55 Amps, which is right in the ballpark. I like the looks of the Balmar 70 amp model (series 6), if only it weren't so expensive ($650)!

Not too familiar with solar, other than I almost never see panels on boats around the marina. Not sure if the Puget Sound cloudy weather (other than summer) makes it ill suited.

mitiempo 10-18-2013 11:06 PM

Re: Continuous duty, non-thermally compensated alternator: options?
 
With a 220 AH battery bank and only alternator charging you do not have enough capacity for one day really. Alternator charging is only efficient up to about 80 - 85% capacity - the last 15 - 20% will take many hours, regardless of alternator size. That means that your usable AH is between 50% - the lowest you should discharge to for long battery life - and say 85%. With a 220 AH bank that leaves you with 77 AH usable and that doesn't meet your daily use of 83.4 AH.

I would repair the alternator or purchase an affordable one, not an expensive Balmar. Leece Neville/Prestolite makes affordable alternators for one. If you repair your alt installing an external regulator is one option that will solve the temp compensation your Hitachi has with its internal reg.

I would also recommend LED's for all interior lights as previously posted. And I would definitely look at solar - it is the only good simple way to reach full charge away from shorepower. And yes solar panels do work well in this area.

Rusty123 10-18-2013 11:36 PM

Continuous duty, non-thermally compensated alternator: options?
 
Wow, I spent a long time formatting that table, but when I hit post, the formatting disappeared [edit - fixed].

Anyway, the lamp reading is with LED, so that's covered, but the concept is sound - a penny saved is a penny earned. The biggest user, by far, is the refrigerator, as expected (almost 30 Ah). Since I don't plan to be away from a marina for more than a day or two at a time, I suppose I could just turn it off on those days.

I also was surprised how much my refer ran -- about 6 min off, 1.5 min on. Seems like a pretty high duty cycle, particularly in this cool weather (it's a Norcold icebox retrofit). I'm going to investigate efficiency improvements (like insulation and lid gasket), since it's such a heavy user.

I took the Hitachi into the shop to be rebuilt today. With the battery monitor, I'll be able to see what it's really doing. I looked on the web for other alternator brands (including Prestolite), but I haven't found anything in the Yanmar frame configuration. Perhaps I'm looking in the wrong places - anybody have a link?

Solar...something new to think about. What did I do with my time B.B? (Before boat).

Rusty123 10-22-2013 08:46 PM

Continuous duty, non-thermally compensated alternator: options?
 
Some new developments in my alternator saga:

Repair quote from the shop is $200. Plus, they tell me this a 35 amp, not 55, as I had thought. I'm not inclined to spend $200 for an undersized alternator - I'd rather put my money towards something more suitable.

Based on lots of research and conversations, my options seem to fall out along these lines.

*Balmar 100 or 125 amp alt, detuned with a Balmar external regulator to 60 amps or so. Max performance, flexibility, and price ($~1,000).

*Balmar or equivalent internally regulated high output alternator, smallest size available 70 or 80 amps. Good performance and moderate cost, but no way to detune (that I know of), so probably too big for my 15 hp engine (~$600).

*New or used & rebuilt 55 amp hitachi. Moderate cost, but dubious performance under load (due to temperature compensation) ~$400. (I haven't found anyone besides hitachi that makes Yanmar-mount alternators, but if there was, that would be another, perhaps better option).

*Chinese hitachi clone. Lowest cost, but dubious performance and reliability. ~$200.

Any suggestions, corrections, or other ideas?

redline 10-30-2013 10:03 AM

Re: Continuous duty, non-thermally compensated alternator: options?
 
One suggestion: several years ago I was looking for a spare alternator (80 A Hitachi on a Yanmar 4JH2TE) partly for an upcoming voyage, partly due to intermittent charging which turned out to be... a poor connection on the alte rnator ground at the engine block (the 80A version is NOT case-grounded, that short black lead is *really* important).

What I did find was a NOS (New Old Stock) original Yanmar alternator that a shop had removed from a newly delivered engine because the boat owner wanted a Balmar or similar upgrade. Cheaper than a rebuild, perfect fit. No better than the original, but I was satisfied with it when it was working properly. You should be able to find one for about half the "chinese hitachi clone" you mention.

newhaul 10-30-2013 12:36 PM

Re: Continuous duty, non-thermally compensated alternator: options?
 
Rusty there are lots of solar panels on boats here in he Puget sound just not many here in our marina I have a small one to charge my house battery and I use independent solar cabin lights when on the hook I'm on E dock.

Rusty123 10-31-2013 01:17 PM

Re: Continuous duty, non-thermally compensated alternator: options?
 
Quote:

Originally Posted by redline (Post 1112219)
What I did find was a NOS (New Old Stock) original Yanmar alternator that a shop had removed from a newly delivered engine because the boat owner wanted a Balmar or similar upgrade. Cheaper than a rebuild, perfect fit. No better than the original, but I was satisfied with it when it was working properly. You should be able to find one for about half the "chinese hitachi clone" you mention.

It's interesting that you suggest this -- I actually purchased a used Hitachi alternator (60 amp) from a friend who had removed it from his engine in place of a Balmar. I have it sitting in my shop, but haven't decided whether to install it. I'm still debating installing an aftermarket alt (actually, what I'm really doing is trying to find a good deal on a Balmar external regulator).

Thanks for the suggestion!


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